Joining the growing trend of replacing lawnmowers and pesticides with plant-eating goats in urban areas, the Congressional Cemetery in Washington, D.C. is enlisting 100 of the voracious herbivores to help tidy up its grounds this month. Among the animals’ chores: clearing vines, ground coverings and poison ivy from the 35-acre site, which is the final resting place of FBI chief J. Edgar Hoover and Civil War photographer Mathew Brady, among other notables.

Why goats? “The revolutionary use of eco-goats eliminates the need for harmful herbicides and prevents the invasive and often foreign species from killing large mature trees in the cemetery’s wooded area, which can fall onto the grounds as a result and damage invaluable historic headstones,” according to a press release. They’re also able to eat plants that are poisonous to humans without getting sick, can chew seeds so they are no longer viable, and tend to prefer the kinds of broad leafy plants that are typically considered weeds.

Enlisting goats for lawn care has become increasingly popular in recent years. Google began using them back in 2009 to trim the overgrowth at its headquarters in Mountain View, California. In June Chicago’s O’Hare International Airport hired them to help tidy up airport grounds. A report from the General Services Administration released this year also noted that goats are cheaper and faster than hiring a crew of landscape workers to do the same job. Since eating is the job, they don’t need a lunch break either.